1. Field of the Invention
This invention relates to soda bottle cap of simple structure that enables discharge of liquid from a soda bottle while keeping high pressure gas inside to maintain the carbonated taste of liquid until it is consumed.
2. Background
Because the commonly used cap for soda bottle that contains carbonated liquid, such as cola, cider, and beer, is simply made of shell (1) and seal (2) as is shown in FIG. 1, the cap should be removed from the bottle (3) before the liquid can be poured from the bottle. As soon as the cap is opened, the high pressure CO.sub.2 gas inside the bottle is released from the bottle. When the cap is closed after use, the space above the carbonated liquid is slowly pressured again by the CO.sub.2 released from the carbonated liquid inside the bottle. When the cap is opened again to pour out the liquid from the bottle, the high pressure CO.sub.2 gas is lost again as this opening and closing of the cap is repeated, the CO.sub.2 gas that is dissolved in the carbonated liquid is lost repeatedly, the carbonated taste of carbonated liquid becomes weak, and the liquid turns stale and flat.
To avoid such problems the soda bottle cap of this invention enables release of liquid from a soda bottle while keeping high pressure up. The soda bottle cap of this invention can be manufactured easily for lost cost as it has simple structure and, therefore, can be used widely on soda bottles for general consumers.